[NET]: Fix loopback crashes when multiqueue is enabled.

From: Patrick McHardy <kaber@trash.net>

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 9820ca1..4a616d7 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -575,7 +575,7 @@
 
 	/* The TX queue control structures */
 	unsigned int			egress_subqueue_count;
-	struct net_device_subqueue	egress_subqueue[0];
+	struct net_device_subqueue	egress_subqueue[1];
 };
 #define to_net_dev(d) container_of(d, struct net_device, dev)